Many unsuccessful attempts have been made to discover workable methods and apparatus for gathering metal nodules from layers of silt at the surface of the sea bed. Nodules, containing such industrially significant metals as manganese, copper, cobalt, nickel, zinc, vanadium, and others, are generally found in the silt layer quite close to the silt/water interface. The silt is generally red clay or silicious or calcareous ooze, and usually has a sticky or adhesive character. The great depths of the water under which the nodule-bearing silt layers exist indicate the desirability of remote controlled, mechanized gathering techniques and apparatus. However, difficulties have been experienced not only with the plugging or blocking of such apparatus by sticky masses of silt and nodules, but also with inadequate removal of stubbornly adherent silt from the nodules. Some of the means heretofore suggested for overcoming these problems introduce exaggerated power requirements which, under present conditions, are economically impracticable. Thus, a need remains for improvements in methods and apparatus for gathering and cleaning metal nodules from the sea bed.